Airship



H. NAATZ AIRSHIP Feb. 3, 1925. 1,524,799

Filed March 30, 1923 2 Sheets-Sheet 1 9K 13- ik )K' J 1 aff J,

Patented Feb. 3, 1925.

HERMANN NAATZ, 0F BERLIN-CHARLOTTENBURG, GERMANY, ASSIGNOR TO LUSTUV, LUFTFAHRTECHNISGHE STUDIEN- UND VEBWERTUNGS-GESELLSCHAFT M. B. 11.,

OF BERLIN, GER-MANY.

AIRSHIP.

Application filed. March 30, 1923. Serial No. 628,850.

1 0 all whom it may concern:

Be it known that I, HERMANN NAATZ, residing at 12 V'Vitzlebenstrasse, Berlin-Charlotte-nburg, Germany, have invented certain new and useful Improvements in Airships, of which the following is a specification.

This invention relates in general to airships and more particularly to an arrangement of bulk-heads in ships of this kind.

It is well known that in large airships one or more bulk-heads are provided in order to prevent the gas pressure in the highest part of the ship from increasing excessively when the ship assumes a slanting position, and in order to prevent the enclosed gas, which might not completely fill the balloon, from travelling to and fro in the interior of the ship. The said increases of pressure at the highest part of the ship render it necessary to strengthen the ships envelope, which involves increased weight, and the travelling of the gas due to a slanting position or tilting of the ship around a transverse axis, is undesirable and interferes with its operations. To avoid these drawbacks the internal space of the balloon is subdivided by bulk-heads, each bulk-head being constructed so as to be capable of resisting a certain minimum gas pressure from one side at least. The rises of pressure and the motions of the gas are then limited to the compartments enclosed between the various bulk-heads and cannot have the effect that they would produce in a dirigible balloon without bulk-heads.

Arrangements of bulk-heads are known in which each transverse partition consists of a straight or flat wall held at both sides by suitable ties. Another known arrangement comprises two spherically curved transverse walls. The former arrangement cannot be used in ships having several gas cells inserted in the outer envelope, and the latter arrangement is coupled with the disadvantage that adeep stricture is produced in the balloon at the seam by which the two hemispherical bulk-heads are joined to the envelope. Besides the two hemispheres have to be kept loaded or under stress in one direction in order to prevent them from losing their shape.

These advantages are avoided by the present invention in accordance with which each bulk-head is made perfectly or substan- Fig. 3 is a section on a vertical plane through the envelope of a non-rigid airship provided with bulk-heads according to the invention.

Fig. 4 is a section through the horizontal middle plane of Fig. 3.

Fig. 5 shows a modified bulk-head arrangement with a middle dividing wall extending from end to end of the envelope of the airship, and

Fig. 6 shows a modified arrangement in which the bulk-heads touch each other.

In the drawing Fig. l a is the envelope and b a cylindrical bulk-head, the radius of the curve of the cylindrical surface 7) being equal to the radius of the envelope (4 so that the lines 72- at which the cylindrical surface I) intersect the body of the envelope (4 form straight sides of a triangle BAB while in Fig. 2 the bulk-head Z2 has the form of an arc ABA which touches the sides of the envelope at at two points A, the sides a forming tangents of the arc ABA. When stresses are applied to the bulk-head in the direction indicated in Fig. 2 by arrows, all of the fibers 0 extending horizontally around the are will be tensioned and these hori zontal fibers 0 alone will take the entire stress, the vertical fibers taking no part of the stress because they are hardly curved or not curved at all. Hence if the latter are made long enough to have no effect on the cross section of the envelope they will remain substantially untensioned and will a-pply no stress to the envelope of the balloon. It is thus seen that the said envelope has stresses applied to it by the horizontal fibers only of the bulk-head, and these only apply the stress tangentially as at the points A, Fig. 2, or at an acute angle at the junction lines a or at any rate the stresses are applied to the envelope (4 in such directions as to cause only a very small component to act at right angles to the surface of the envelope a. Practical experience has revealed the additional-advantage that, since the lines of intersection n are oblique with. respect to the longitudinal axis of the balloon, the said components are counteracted and balanced by the considerable circumferential tension of the envelope. In consequence of this ci-rcumferential tension the said components extending at right angles to the surface of the envelope produce very small constrictions which. are practically unnoticeable. It is thus seen that by making the bulk-head in the shape of a part of a cylinder, the deformation of the balloon, which otherwise is very diflicult to prevent, is avoided entirely in a most simple manner. This cylindrical form of bulk-head also constitutes a wall which, when subjected to stresses, is. stressed in a simple and easily calculable manner, the stress being always: 5 m r, where 2) denotes the pressure per squaremeter-applied at one side and r is the radiusof the curve of the wall. The novel bulk-head can thus be made lighter than the bulk-heads employed hitherto which involved ditiicult calculations. A further considerable advantage of the cylindrical bulk-head is the fact that, in its unstressed condition, it already has the shape of the stressed wall so thatit commences acting as soon as a stress is applied.

As they only take stresses from one side, the cylindrical bulk-heads are preferably arranged inpairs as illustrated in Figs. 3 and 4:. The space in the balloon with the envelope a in these figures is subdivided into 5 compartments 1, 2, 3, 4 and fi by two bulk-head systems each comprising, two bulk-heads d, e and f, g'respectively. 'When the balloon goes into a slanting position two bulk-heads only, named (Z and f or c and g respectively, will be stressed. The unstressed walls will be bulged inwards so as to enable the pressures between the chambers 2 or 4 and the next chamber above to be equalized. In order to prevent the bulkheads from being bulged in too much the two bulk-heads of each pair are preferably placed as close as possible to each other so as to keep down the volume of the intervening space or chamber 2 or at and to reduce the quantity of gas required for balancing the pressures, or that passes out from a compartment for this purpose. If the bulging in of the bulk-heads is to be entirely avoided, valves or the like maybe provided in each wall which automatically allow the gas to travel towards the concave side of the cylindrical wall only. Valve arrangements of this kindare shown in Fig. 3 in which the bulk-heads f and have openings h, 6 adapted to be closed and opened by fabric flap valves and Z. When the airship goes into a slanting position, so that for example the compartment 5 lies higher than the compartment 3 the valve is willbe moved by the travelling gas towards the compartment 4 so as to close the opening it in the bulk-head f, while the flap Z is lifted away from the opening 2' so as to establish communication between the comartments 4- and' 5 and revent the bulkhead 5/ from being stressed and bulged in when the bulk-head is tensicned.

The various compartments of a balloon or airsl ip with cylindrical bulk-heads according to, the invention may be constructed in the'form of chambersprovided with balloonets for keeping the gas envelopes taut. but it will be found more advantageous, particularly in the case of large ships, to provide the various compartments with cells and to introduce the gas into the cells. lfhese gas cells press against the interior of the envelope and against the bulk-heads, and contract more or at their bottom ends according to the amount of gas they contain. 7

In the modification shown inv Fig. 5, a

balloon with cylindrical bulk-heads and a middle vertical longitudinal wall 1S shown.

The envelope a is divided into compartments by bulk-heads, as. m, p and r, s, with cyliin drical surfaces and by the longitudinal iniddle wall t. The wall 2. may intersectthe bulk-heads in any desired manner, while the bulk-heads must be curved so that the envelope a forms a tangent of the curve of the bulk-heads, or at least these lattermust form very acute angles with the envelope a. The bulkheads with cylindrical surfaces may also be arranged in a similar manner in' balloons having more than one longitudi nalconstricting or separating wall.

In Fig. 6 is shown a modified bulkhead arrangement in which the curved bulkheads CZ", e and 7, g respectively touch each other.

In rigid airships in which the gas cells are not placed in a fabric envelope, but in a skeleton which carries the external fabric envelope, the edges of the cylindrical bulkheads are connected to the said skeleton.

I claim 1. In an airship, an envelope and a transversely extending curved bulkhead in the envelope, eachsection of said bulkhead taken in planes at right angles to the axis of curvature conforming to the arc of a circle.

2. In an airship, an envelope and trans versely extending bulkheads in the envelope, said, bulkheads conforming in shape to a portion of a cylindrical surface having a radius of curvature equal to the radius of curvature of said envelope.

3. In an airship, an envelope, transversely extending bulkheads in the envelope, said bulkheads conforming in shape to a portion of a cylindrical surface having aradius of curvature equal to the radius of curvature of said envelope, and means in the bulkheads for permitting gas to pass through the bulkheads.

4. In an airship, an envelope, and transversely extending bulkheads in the envelope arranged in pairs, said bulkheads conform-t ing in shape to a portion of a cylindrical surface having a radius of curvature equal to the radius of curvature of said envelope and said bulkheads being so placed that their convex faces are opposed to each other.

5. In an airship, an envelope, and transversely extending bulkheads in the envelope arranged in pairs, said bulkheads conform ing in shape to a portion of a cylindrical surface having a radius of curvature equal to the radius of curvature of said envelope, each of said pairs of bulkheads being so arranged that their convex faces are opposed to each other and closely adjacent.

6. In an airship, an envelope, transversely extending bulkheads in the envelope arranged an pairs, said bulkheads conforming in shape to a portion of acylindrical surface having a radius of curvature equal to the radius of curvature of said envelope and arranged so the convex faces of a pair are opposed to each other, and means for permitting gas to pass through the bulkheads.

7 In an airship, an envelope, a transversely extending curved bulkhead in the envelope, each section of said bulkhead taken in planes at right angles to the axis of curvature conforming to the arc of a circle, and a longitudinal Wall extending through the envelope.

8. In an airship, an envelope, transversely extending bulkheads in the envelope arranged in pairs, said bulkheads conforming in shape to a portion of a cylindrical surface having a radius of curvature equal to the radius of curvature of said envelope, the convex faces of each pair of bulkheads being opposed to each other, and a longitudi nal Wall extending through the said envelope.

In testimony whereof I affix my signature in presence of a Witness.

HER-MANN NAATZ. Witness E. HGLZERMANN. 

